1. Technical Field
The present invention relates to a method of manufacturing a field emission device and, more particularly, to a method of manufacturing a stable and reliable field emission device.
2. Related Art
Field emission devices emit electrons from an emitter formed on a cathode by forming a strong electric field around the emitter. Field emission devices are used in a wide range of applications including field emission displays (FEDs) which are flat panel displays. FEDs produce an image by colliding electrons emitted from a field emission device with a phosphor layer formed on an anode. Since FEDs are only a few centimeters thick and feature a wide viewing angle, low power consumption and low manufacturing costs, FEDs together with liquid crystal displays (LCDs) and plasma display panels (PDPs) are attracting attention as the next generation of display devices.
Field emission devices can also be used in backlight units (BLU) of LCDs. LCDs display an image on a front surface by selectively transmitting light emitted by a light source disposed at the rear side of an LCD panel. Examples of the light source which can be disposed at the rear side of an LCD panel include a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (EEFL), and a light emitting diode (LED). Besides these, a field emission type backlight unit can also be used as the light source. Field emission type backlight units, in principle, have the same driving mechanism for luminance as FEDs. However, field emission type backlight units are different from FEDs in that field emission type backlight units do not display an image but only function as light sources. Field emission type backlight units attract attention as the next generation of backlight units for LCDs because of their thin structure, low manufacturing costs, and brightness control. Field emission devices can also be applied to various systems using electron emission, such as X-ray tubes, microwave amplifiers, and flat lamps.
Micro tips formed of a metal, such as molybdenum (Mo), have been used as emitters of field emission devices. However, recently, carbon nanotubes (CNTs) having good electron emission properties have often been used as emitters. Field emission devices using CNT emitters have the advantages of low cost, a low driving voltage, and high chemical and mechanical stability. CNT emitters may be formed by printing CNT paste or by directly growing CNTs using chemical vapor deposition (CVD). The direct growing of CNTs requires high growth temperature and complex synthesis conditions, thereby making it difficult to achieve mass production. Accordingly, CNT paste has become preferable in recent years.